Percutaneous transvenous treatment has become the elective therapy for varicocele because it is a simple, safe, economic and reliable procedure. The presence of proximal anastomoses connecting a competent valved spermatic trunk with the renal vein can be responsible for a varicocele and make its treatment difficult. In such cases; the valve of the spermatic venous trunk can be bypassed using an open-ended guidewire with a removable mandril core, and then injecting the sclerosing agent through the guide. Moreover, the guidewire can facilitate the insertion of the catheter through the competent valve, thus allowing the placement of Gianturco coils. During the past 12 months we have successfully treated 4 patients affected by varicocele with competent valved venous trunk using the open-ended guidewire.